1. Field of the Invention
The present invention relates to an aseismatic device, and more particularly, to an aseismatic device having a spring pin and a positioning ball able to absorb the seismic energy.
2. Description of the Prior Art
As semiconductor technology improves and the requirements of electronic products increase, the semiconductor manufacturers annually invest more and more capital to purchase new equipment and to construct new factories. Take a fab, an upstream manufacturer in the semiconductor industries, as an example. Many wafer manufacturers have launched a mass production of 12-inch wafers in a critical dimension of 0.13 μm or less than 0.13 μm. For these wafer manufactures, although the unit cost is effectively reduced due to the large area of 12-inch wafers, the cost of 12-inch wafers is relatively higher in comparison with 8-inch wafers. Consequently, once the 12-inch wafers are damaged in the course of transporting due to human ignorance or unexpected disaster (e.g. earthquake), the loss is higher.
Since the semiconductor technology improves, more manufacturing processes are required than ever. Normally, the semiconductor components require hundreds of different processes to be accomplished, thus, it requires a huge capacity for a fab to load necessary equipment. In addition, it also requires sufficient space and proper transport system for delivering the wafers in process or the completed wafer products. Therefore, a large amount of fabs adopt an overhead hoist transport (OHT) system for delivering the wafers. Since the OHT system delivers the wafers with a track suspended from the ceiling, the space usage is more efficient.
Please refer to FIG. 1. FIG. 1 is a schematic diagram of a conventional OHT system 20 installed in a fab 10. As shown in FIG. 1, considering the construction cost, the fab 10 normally includes an administrative building 12 and a factory building 14 having clean rooms (not shown) in it. The administrative building 12 and the factory building 14 are connected by an elevated walkway 16. The OHT system is suspended from the ceiling (not shown) of the administrative building 12 and the factory building 14 so that the wafers are delivered among different clean rooms (not shown) or between the administrative building 12 and the factory building 14.
Please refer to FIG. 2. FIG. 2 is a schematic diagram of the conventional OHT system 20 shown in FIG. 1. As shown in FIG. 2, the OHT system 20 includes a track 22 suspended from the ceiling (not shown) by a plurality of supporting rods 24. The track 22 allows at least a wafer trolley 26 to travel along so that the wafers (not shown) are delivered among different clean rooms (not shown).
The conventional OHT system 20 is able to deliver the wafers without requiring too much space. However, once an earthquake occurs, the wafers tend to be damaged. The reason is that the ceiling (not shown) bears the OHT system 20 and the wafers (not shown). This extra burden has not been taken into consideration while the administrative building 12 or the factory building 14 was constructed. As a result, the wafers (not shown), the OHT system 20, or even the fab (shown in FIG. 1) are easily damaged.
Therefore, an OHT system having aseismatic ability is eagerly required for preventing damage during an earthquake.